tests.py now allows parts of projects to be tested without finding an implementation.

NopSCADlib blurb now scraped from libtest.scad.
libtest.scad no longer required and lack of it is used to detect a project.

core.scad

@@ -18,7 +18,7 @@
 //
 
 //
-// Include this file to use the miniumum library plus screws, nuts and washers
+// Include this file to use the minimum library plus screws, nuts and washers
 //
 include <utils/core/core.scad>
 //

global_defs.scad

@@ -33,7 +33,7 @@ $exploded       = is_undef($explode)         ? 0      : $explode;         // 1 f
 layer_height    = is_undef($layer_height)    ? 0.25   : $layer_height;    // layer heigth when printing
 extrusion_width = is_undef($extrusion_width) ? 0.5    : $extrusion_width; // filament width when printing
 nozzle          = is_undef($nozzle)          ? 0.45   : $nozzle;          // 3D printer nozzle
-cnc_bit_r       = is_undef($cnc_bit_r)       ? 1.2    : $cnc_bit_r;       // miniumum tool radius when milling 2D objects
+cnc_bit_r       = is_undef($cnc_bit_r)       ? 1.2    : $cnc_bit_r;       // minimum tool radius when milling 2D objects
 pp1_colour      = is_undef($pp1_colour)      ? [0, 146/255, 0] : $pp1_colour; // printed part colour 1, RepRap logo colour
 pp2_colour      = is_undef($pp2_colour)      ? "red"  : $pp2_colour;      // printed part colour 2
 pp3_colour      = is_undef($pp3_colour)      ? "blue" : $pp3_colour;      // printed part colour 3

libtest.scad

@@ -17,6 +17,23 @@
 // If not, see <https://www.gnu.org/licenses/>.
 //
 
+//!# NopSCADlib
+//! An ever expanding library of parts modelled in OpenSCAD useful for 3D printers and enclosures for electronics, etc.
+//!
+//! It contains lots of vitamins (the RepRap term for non-printed parts), some general purpose printed parts and some utilities.
+//! There are also Python scripts to generate Bills of Materials (BOMs),
+//! STL files for all the printed parts, DXF files for CNC routed parts in a project and a manual containing assembly
+//! instructions and exploded views by scraping markdown embedded in OpenSCAD comments, [see scripts](scripts/readme.md).
+//!
+//! A simple example project can be found [here](examples/MainsBreakOutBox/readme.md).
+//!
+//! For more examples of what it can make see the [gallery](gallery/readme.md).
+//!
+//! The license is GNU General Public License v3.0, see [COPYING](COPYING).
+//!
+//! See [usage](docs/usage.md) for requirements, installation instructions and a usage guide.
+//!
+//! <img src="libtest.png" width="100%"/>
 //
 // This file shows all the parts in the library.
 //

readme.md

@@ -1,10 +1,12 @@
 # NopSCADlib
 An ever expanding library of parts modelled in OpenSCAD useful for 3D printers and enclosures for electronics, etc.
 
-It contains lots of vitamins (the RepRap term for non-printed parts), some general purpose printed parts and
-some utilities. There are also Python scripts to generate Bills of Materials (BOMs),
- STL files for all the printed parts, DXF files for CNC routed parts in a project and a manual containing assembly
-instructions and exploded views by scraping markdown embedded in OpenSCAD comments, [see scripts](scripts/readme.md). A simple example project can be found [here](examples/MainsBreakOutBox/readme.md).
+It contains lots of vitamins (the RepRap term for non-printed parts), some general purpose printed parts and some utilities.
+There are also Python scripts to generate Bills of Materials (BOMs),
+STL files for all the printed parts, DXF files for CNC routed parts in a project and a manual containing assembly
+instructions and exploded views by scraping markdown embedded in OpenSCAD comments, [see scripts](scripts/readme.md).
+
+A simple example project can be found [here](examples/MainsBreakOutBox/readme.md).
 
 For more examples of what it can make see the [gallery](gallery/readme.md).
 
@@ -20,23 +22,23 @@ See [usage](docs/usage.md) for requirements, installation instructions and a usa
 <th align="left"> Vitamins A-I </th><th align="left"> Vitamins J-Q </th><th align="left"> Vitamins R-Z </th><th align="left"> Printed </th><th align="left"> Utilities </th><th align="left"> Core Utilities </th></tr>
 <tr><td> <a href = "#Axials">Axials</a> </td><td> <a href = "#Jack">Jack</a> </td><td> <a href = "#Rails">Rails</a> </td><td> <a href = "#Box">Box</a> </td><td> <a href = "#Annotation">Annotation</a> </td><td> <a href = "#BOM">BOM</a> </td></tr>
 <tr><td> <a href = "#Ball_bearings">Ball_bearings</a> </td><td> <a href = "#KP_pillow_blocks">KP_pillow_blocks</a> </td><td> <a href = "#Ring_terminals">Ring_terminals</a> </td><td> <a href = "#Butt_box">Butt_box</a> </td><td> <a href = "#Bezier">Bezier</a> </td><td> <a href = "#Clip">Clip</a> </td></tr>
-<tr><td> <a href = "#Batteries">Batteries</a> </td><td> <a href = "#LDRs">LDRs</a> </td><td> <a href = "#Rockers">Rockers</a> </td><td> <a href = "#Cable_grommets">Cable_grommets</a> </td><td> <a href = "#Dogbones">Dogbones</a> </td><td> <a href = "#Global">Global</a> </td></tr>
-<tr><td> <a href = "#Belts">Belts</a> </td><td> <a href = "#LED_meters">LED_meters</a> </td><td> <a href = "#Rod">Rod</a> </td><td> <a href = "#Carriers">Carriers</a> </td><td> <a href = "#Fillet">Fillet</a> </td><td> <a href = "#Polyholes">Polyholes</a> </td></tr>
-<tr><td> <a href = "#Blowers">Blowers</a> </td><td> <a href = "#LEDs">LEDs</a> </td><td> <a href = "#SCS_bearing_blocks">SCS_bearing_blocks</a> </td><td> <a href = "#Corner_block">Corner_block</a> </td><td> <a href = "#Gears">Gears</a> </td><td> <a href = "#Rounded_rectangle">Rounded_rectangle</a> </td></tr>
-<tr><td> <a href = "#Bulldogs">Bulldogs</a> </td><td> <a href = "#Leadnuts">Leadnuts</a> </td><td> <a href = "#SK_brackets">SK_brackets</a> </td><td> <a href = "#Door_hinge">Door_hinge</a> </td><td> <a href = "#Hanging_hole">Hanging_hole</a> </td><td> <a href = "#Sphere">Sphere</a> </td></tr>
-<tr><td> <a href = "#Buttons">Buttons</a> </td><td> <a href = "#Light_strips">Light_strips</a> </td><td> <a href = "#SMDs">SMDs</a> </td><td> <a href = "#Door_latch">Door_latch</a> </td><td> <a href = "#Horiholes">Horiholes</a> </td><td> <a href = "#Teardrops">Teardrops</a> </td></tr>
-<tr><td> <a href = "#Cable_strips">Cable_strips</a> </td><td> <a href = "#Linear_bearings">Linear_bearings</a> </td><td> <a href = "#SSRs">SSRs</a> </td><td> <a href = "#Fan_guard">Fan_guard</a> </td><td> <a href = "#Layout">Layout</a> </td><td></td></tr>
-<tr><td> <a href = "#Cameras">Cameras</a> </td><td> <a href = "#Magnets">Magnets</a> </td><td> <a href = "#Screws">Screws</a> </td><td> <a href = "#Fixing_block">Fixing_block</a> </td><td> <a href = "#Maths">Maths</a> </td><td></td></tr>
-<tr><td> <a href = "#Circlips">Circlips</a> </td><td> <a href = "#Mains_sockets">Mains_sockets</a> </td><td> <a href = "#Sealing_strip">Sealing_strip</a> </td><td> <a href = "#Flat_hinge">Flat_hinge</a> </td><td> <a href = "#Offset">Offset</a> </td><td></td></tr>
-<tr><td> <a href = "#Components">Components</a> </td><td> <a href = "#Microswitches">Microswitches</a> </td><td> <a href = "#Sheets">Sheets</a> </td><td> <a href = "#Foot">Foot</a> </td><td> <a href = "#Quadrant">Quadrant</a> </td><td></td></tr>
-<tr><td> <a href = "#DIP">DIP</a> </td><td> <a href = "#Microview">Microview</a> </td><td> <a href = "#Spades">Spades</a> </td><td> <a href = "#Handle">Handle</a> </td><td> <a href = "#Round">Round</a> </td><td></td></tr>
-<tr><td> <a href = "#D_connectors">D_connectors</a> </td><td> <a href = "#Modules">Modules</a> </td><td> <a href = "#Spools">Spools</a> </td><td> <a href = "#PCB_mount">PCB_mount</a> </td><td> <a href = "#Rounded_cylinder">Rounded_cylinder</a> </td><td></td></tr>
-<tr><td> <a href = "#Displays">Displays</a> </td><td> <a href = "#Nuts">Nuts</a> </td><td> <a href = "#Springs">Springs</a> </td><td> <a href = "#PSU_shroud">PSU_shroud</a> </td><td> <a href = "#Rounded_polygon">Rounded_polygon</a> </td><td></td></tr>
-<tr><td> <a href = "#Extrusion_brackets">Extrusion_brackets</a> </td><td> <a href = "#O_ring">O_ring</a> </td><td> <a href = "#Stepper_motors">Stepper_motors</a> </td><td> <a href = "#Printed_box">Printed_box</a> </td><td> <a href = "#Sector">Sector</a> </td><td></td></tr>
-<tr><td> <a href = "#Extrusions">Extrusions</a> </td><td> <a href = "#Opengrab">Opengrab</a> </td><td> <a href = "#Swiss_clips">Swiss_clips</a> </td><td> <a href = "#Ribbon_clamp">Ribbon_clamp</a> </td><td> <a href = "#Sweep">Sweep</a> </td><td></td></tr>
-<tr><td> <a href = "#Fans">Fans</a> </td><td> <a href = "#PCB">PCB</a> </td><td> <a href = "#Toggles">Toggles</a> </td><td> <a href = "#SSR_shroud">SSR_shroud</a> </td><td> <a href = "#Thread">Thread</a> </td><td></td></tr>
-<tr><td> <a href = "#Fuseholder">Fuseholder</a> </td><td> <a href = "#PCBs">PCBs</a> </td><td> <a href = "#Transformers">Transformers</a> </td><td> <a href = "#Screw_knob">Screw_knob</a> </td><td> <a href = "#Tube">Tube</a> </td><td></td></tr>
-<tr><td> <a href = "#Geared_steppers">Geared_steppers</a> </td><td> <a href = "#PSUs">PSUs</a> </td><td> <a href = "#Tubings">Tubings</a> </td><td> <a href = "#Socket_box">Socket_box</a> </td><td></td><td></td></tr>
+<tr><td> <a href = "#Batteries">Batteries</a> </td><td> <a href = "#LDRs">LDRs</a> </td><td> <a href = "#Rockers">Rockers</a> </td><td> <a href = "#Cable_grommets">Cable_grommets</a> </td><td> <a href = "#Catenary">Catenary</a> </td><td> <a href = "#Global">Global</a> </td></tr>
+<tr><td> <a href = "#Belts">Belts</a> </td><td> <a href = "#LED_meters">LED_meters</a> </td><td> <a href = "#Rod">Rod</a> </td><td> <a href = "#Carriers">Carriers</a> </td><td> <a href = "#Dogbones">Dogbones</a> </td><td> <a href = "#Polyholes">Polyholes</a> </td></tr>
+<tr><td> <a href = "#Blowers">Blowers</a> </td><td> <a href = "#LEDs">LEDs</a> </td><td> <a href = "#SCS_bearing_blocks">SCS_bearing_blocks</a> </td><td> <a href = "#Corner_block">Corner_block</a> </td><td> <a href = "#Fillet">Fillet</a> </td><td> <a href = "#Rounded_rectangle">Rounded_rectangle</a> </td></tr>
+<tr><td> <a href = "#Bulldogs">Bulldogs</a> </td><td> <a href = "#Leadnuts">Leadnuts</a> </td><td> <a href = "#SK_brackets">SK_brackets</a> </td><td> <a href = "#Door_hinge">Door_hinge</a> </td><td> <a href = "#Gears">Gears</a> </td><td> <a href = "#Sphere">Sphere</a> </td></tr>
+<tr><td> <a href = "#Buttons">Buttons</a> </td><td> <a href = "#Light_strips">Light_strips</a> </td><td> <a href = "#SMDs">SMDs</a> </td><td> <a href = "#Door_latch">Door_latch</a> </td><td> <a href = "#Hanging_hole">Hanging_hole</a> </td><td> <a href = "#Teardrops">Teardrops</a> </td></tr>
+<tr><td> <a href = "#Cable_strips">Cable_strips</a> </td><td> <a href = "#Linear_bearings">Linear_bearings</a> </td><td> <a href = "#SSRs">SSRs</a> </td><td> <a href = "#Fan_guard">Fan_guard</a> </td><td> <a href = "#Horiholes">Horiholes</a> </td><td></td></tr>
+<tr><td> <a href = "#Cameras">Cameras</a> </td><td> <a href = "#Magnets">Magnets</a> </td><td> <a href = "#Screws">Screws</a> </td><td> <a href = "#Fixing_block">Fixing_block</a> </td><td> <a href = "#Layout">Layout</a> </td><td></td></tr>
+<tr><td> <a href = "#Circlips">Circlips</a> </td><td> <a href = "#Mains_sockets">Mains_sockets</a> </td><td> <a href = "#Sealing_strip">Sealing_strip</a> </td><td> <a href = "#Flat_hinge">Flat_hinge</a> </td><td> <a href = "#Maths">Maths</a> </td><td></td></tr>
+<tr><td> <a href = "#Components">Components</a> </td><td> <a href = "#Microswitches">Microswitches</a> </td><td> <a href = "#Sheets">Sheets</a> </td><td> <a href = "#Foot">Foot</a> </td><td> <a href = "#Offset">Offset</a> </td><td></td></tr>
+<tr><td> <a href = "#DIP">DIP</a> </td><td> <a href = "#Microview">Microview</a> </td><td> <a href = "#Spades">Spades</a> </td><td> <a href = "#Handle">Handle</a> </td><td> <a href = "#Quadrant">Quadrant</a> </td><td></td></tr>
+<tr><td> <a href = "#D_connectors">D_connectors</a> </td><td> <a href = "#Modules">Modules</a> </td><td> <a href = "#Spools">Spools</a> </td><td> <a href = "#PCB_mount">PCB_mount</a> </td><td> <a href = "#Round">Round</a> </td><td></td></tr>
+<tr><td> <a href = "#Displays">Displays</a> </td><td> <a href = "#Nuts">Nuts</a> </td><td> <a href = "#Springs">Springs</a> </td><td> <a href = "#PSU_shroud">PSU_shroud</a> </td><td> <a href = "#Rounded_cylinder">Rounded_cylinder</a> </td><td></td></tr>
+<tr><td> <a href = "#Extrusion_brackets">Extrusion_brackets</a> </td><td> <a href = "#O_ring">O_ring</a> </td><td> <a href = "#Stepper_motors">Stepper_motors</a> </td><td> <a href = "#Printed_box">Printed_box</a> </td><td> <a href = "#Rounded_polygon">Rounded_polygon</a> </td><td></td></tr>
+<tr><td> <a href = "#Extrusions">Extrusions</a> </td><td> <a href = "#Opengrab">Opengrab</a> </td><td> <a href = "#Swiss_clips">Swiss_clips</a> </td><td> <a href = "#Ribbon_clamp">Ribbon_clamp</a> </td><td> <a href = "#Sector">Sector</a> </td><td></td></tr>
+<tr><td> <a href = "#Fans">Fans</a> </td><td> <a href = "#PCB">PCB</a> </td><td> <a href = "#Toggles">Toggles</a> </td><td> <a href = "#SSR_shroud">SSR_shroud</a> </td><td> <a href = "#Sweep">Sweep</a> </td><td></td></tr>
+<tr><td> <a href = "#Fuseholder">Fuseholder</a> </td><td> <a href = "#PCBs">PCBs</a> </td><td> <a href = "#Transformers">Transformers</a> </td><td> <a href = "#Screw_knob">Screw_knob</a> </td><td> <a href = "#Thread">Thread</a> </td><td></td></tr>
+<tr><td> <a href = "#Geared_steppers">Geared_steppers</a> </td><td> <a href = "#PSUs">PSUs</a> </td><td> <a href = "#Tubings">Tubings</a> </td><td> <a href = "#Socket_box">Socket_box</a> </td><td> <a href = "#Tube">Tube</a> </td><td></td></tr>
 <tr><td> <a href = "#Green_terminals">Green_terminals</a> </td><td> <a href = "#Panel_meters">Panel_meters</a> </td><td> <a href = "#Variacs">Variacs</a> </td><td> <a href = "#Strap_handle">Strap_handle</a> </td><td></td><td></td></tr>
 <tr><td> <a href = "#Hot_ends">Hot_ends</a> </td><td> <a href = "#Pillars">Pillars</a> </td><td> <a href = "#Veroboard">Veroboard</a> </td><td></td><td></td><td></td></tr>
 <tr><td> <a href = "#Hygrometer">Hygrometer</a> </td><td> <a href = "#Pin_headers">Pin_headers</a> </td><td> <a href = "#Washers">Washers</a> </td><td></td><td></td><td></td></tr>
@@ -403,7 +405,7 @@ PCB mounted buttons. Can optionally have a coloured cap
 ## Cable_strips
 A strip of polypropylene used with ribbon cable to make a cable flexible in one direction only.
 
-Modelled with a Bezier spline, which is not quite the same as a miniumum energy curve but very close, epecially
+Modelled with a Bezier spline, which is not quite the same as a minimum energy curve but very close, epecially
 near the extreme positions, where the model needs to be accurate.
 
 When the sides are constrained then a circular model is more accurate.
@@ -2332,14 +2334,14 @@ PCBs and perfboard with optional components. The shape can be a rectangle with o
 |   1 | ```pcb(EnviroPlus)``` |  Enviro+ |
 |   1 | ```pcb(ExtruderPCB)``` |  Extruder connection PCB |
 |   1 | ```pcb(Keyes5p1)``` |  Keyes5.1 Arduino Uno expansion board |
+|   1 | ```pcb(MP1584EN)``` |  MP1584EN 3A buck converter |
 |   1 | ```pcb(MT3608)``` |  MT3608 boost converter module |
-|   1 | ```pcb(Melzi)``` |  Melzi electronics |
-|   5 |  |  Micro SD card |
+|   4 |  |  Micro SD card |
 |   1 | ```molex_254(2)``` |  Molex KK header 2 way |
 |   1 | ```molex_254(3)``` |  Molex KK header 3 way |
 |  16 | ```nut(M2_nut, nyloc = true)``` |  Nut M2 x 1.6mm nyloc |
 |  34 | ```nut(M2p5_nut, nyloc = true)``` |  Nut M2.5 x 2.2mm nyloc |
-|  16 | ```nut(M3_nut, nyloc = true)``` |  Nut M3 x 2.4mm nyloc |
+|  12 | ```nut(M3_nut, nyloc = true)``` |  Nut M3 x 2.4mm nyloc |
 |  12 | ```nut(M4_nut, nyloc = true)``` |  Nut M4 x 3.2mm nyloc |
 |   1 | ```pcb(PI_IO)``` |  PI_IO V2 |
 |   1 | ```pcb(PSU12V1A)``` |  PSU 12V 1A |
@@ -2355,24 +2357,21 @@ PCBs and perfboard with optional components. The shape can be a rectangle with o
 |   1 | ```pcb(RPI0)``` |  Raspberry Pi Zero |
 |  12 | ```screw(M2_cap_screw, 16)``` |  Screw M2 cap x 16mm |
 |   4 | ```screw(M2_cap_screw, 20)``` |  Screw M2 cap x 20mm |
-|   2 | ```screw(M2p5_cap_screw, 16)``` |  Screw M2.5 cap x 16mm |
-|   4 | ```screw(M2p5_cap_screw, 20)``` |  Screw M2.5 cap x 20mm |
-|   4 | ```screw(M2p5_cap_screw, 25)``` |  Screw M2.5 cap x 25mm |
+|   2 | ```screw(M2p5_cap_screw, 20)``` |  Screw M2.5 cap x 20mm |
+|   8 | ```screw(M2p5_cap_screw, 25)``` |  Screw M2.5 cap x 25mm |
 |   8 | ```screw(M2p5_cap_screw, 30)``` |  Screw M2.5 cap x 30mm |
 |   4 | ```screw(M2p5_pan_screw, 20)``` |  Screw M2.5 pan x 20mm |
 |  12 | ```screw(M2p5_pan_screw, 25)``` |  Screw M2.5 pan x 25mm |
 |   4 | ```screw(M3_cap_screw, 16)``` |  Screw M3 cap x 16mm |
 |   8 | ```screw(M3_cap_screw, 30)``` |  Screw M3 cap x 30mm |
-|   4 | ```screw(M3_cap_screw, 35)``` |  Screw M3 cap x 35mm |
 |  12 | ```screw(M4_cap_screw, 35)``` |  Screw M4 cap x 35mm |
 |   1 | ```pcb(TP4056)``` |  TP4056 Li-lon Battery charger module |
 |   3 | ```terminal_35(2)``` |  Terminal block 2 way 3.5mm |
 |   2 | ```green_terminal(gt_2p54, 4)``` |  Terminal block 4 way 0.1" |
-|   1 |  |  USB A to Mini B lead |
 |   1 | ```pcb(WD2002SJ)``` |  WD2002SJ Buck Boost DC-DC converter |
 |  16 | ```washer(M2_washer)``` |  Washer  M2 x 5mm x 0.3mm |
 |  34 | ```washer(M2p5_washer)``` |  Washer  M2.5 x 5.9mm x 0.5mm |
-|  16 | ```washer(M3_washer)``` |  Washer  M3 x 7mm x 0.5mm |
+|  12 | ```washer(M3_washer)``` |  Washer  M3 x 7mm x 0.5mm |
 |  12 | ```washer(M4_washer)``` |  Washer  M4 x 9mm x 0.8mm |
 |   1 | ```pcb(ZC_A0591)``` |  ZC-A0591 ULN2003 driver PCB |
 
@@ -2383,22 +2382,21 @@ PCBs and perfboard with optional components. The shape can be a rectangle with o
 |   4 | pcb_spacer2070.stl |
 |   4 | pcb_spacer2080.stl |
 |   4 | pcb_spacer2090.stl |
-|   4 | pcb_spacer25100.stl |
 |   4 | pcb_spacer25110.stl |
 |   4 | pcb_spacer25120.stl |
-|   4 | pcb_spacer25130_2.stl |
+|   4 | pcb_spacer25130.stl |
 |   4 | pcb_spacer25140_2.stl |
 |   4 | pcb_spacer25150_2.stl |
-|   4 | pcb_spacer25180.stl |
+|   4 | pcb_spacer25160_2.stl |
 |   4 | pcb_spacer25190.stl |
-|   2 | pcb_spacer2570.stl |
-|   4 | pcb_spacer30160.stl |
+|   4 | pcb_spacer25200.stl |
+|   2 | pcb_spacer2580.stl |
 |   4 | pcb_spacer30170.stl |
-|   4 | pcb_spacer30230.stl |
+|   4 | pcb_spacer30180.stl |
 |   4 | pcb_spacer3050.stl |
-|   4 | pcb_spacer40200.stl |
 |   4 | pcb_spacer40210.stl |
 |   4 | pcb_spacer40220.stl |
+|   4 | pcb_spacer40230.stl |
 
 
 <a href="#top">Top</a>
@@ -3426,7 +3424,7 @@ NEMA stepper motor model.
 ### Modules
 | Module | Description |
 |:--- |:--- |
-| ```NEMA(type, shaft_angle = 0)``` | Draw specified NEMA stepper motor |
+| ```NEMA(type, shaft_angle = 0, jst_connector = false)``` | Draw specified NEMA stepper motor |
 | ```NEMA_outline(type)``` | 2D outline |
 | ```NEMA_screw_positions(type, n = 4)``` | Positions children at the screw holes |
 | ```NEMA_screws(type, screw, n = 4, screw_length = 8, earth = undef)``` | Place screws and optional earth tag |
@@ -5245,6 +5243,36 @@ Bezier curves and function to get and adjust the length or minimum z point.
 ![bezier](tests/png/bezier.png)
 
 
+<a href="#top">Top</a>
+
+---
+<a name="Catenary"></a>
+## Catenary
+Catenary curve to model hanging wires, etc.
+
+Although the equation of the curve is simply ```y = a cosh(x / a)``` there is no explicit formula to calculate the constant ```a``` or the range of ```x``` given the
+length of the cable and the end point coordinates. See <https://en.wikipedia.org/wiki/Catenary#Determining_parameters>. The Newton-Raphson method is used to find
+```a``` numerically, see <https://en.wikipedia.org/wiki/Newton%27s_method>.
+
+The coordinates of the lowest point on the curve can be retrieved by calling ```catenary_points()``` with ```steps``` equal to zero.
+
+
+[utils/catenary.scad](utils/catenary.scad) Implementation.
+
+[tests/catenary.scad](tests/catenary.scad) Code for this example.
+
+### Functions
+| Function | Description |
+|:--- |:--- |
+| ```catenary(t, a)``` | Parametric catenary function linear along the length of the curve. |
+| ```catenary_ds_by_da(d, a)``` | First derivative of the length with respect to ```a```. |
+| ```catenary_find_a(d, l, a = 1, best_e = inf, best_a = 1)``` | Find the catenary constant ```a```, given half the horizontal span and the length. |
+| ```catenary_points(l, x, y, steps = 100)``` | Returns a list of 2D points on the curve that goes from the origin to ```(x,y)``` and has length ```l```. |
+| ```catenary_s(d, a)``` | Length of a symmetric catenary with width ```2d```. |
+
+![catenary](tests/png/catenary.png)
+
+
 <a href="#top">Top</a>
 
 ---
@@ -5361,6 +5389,8 @@ Method to print holes in mid air. See <https://hydraraptor.blogspot.com/2014/03/
 ## Horiholes
 Utilities for depicting the staircase slicing of horizontal holes made with [`teardrop_plus()`](#teardrops), see <https://hydraraptor.blogspot.com/2020/07/horiholes-2.html>
 
+```horicylinder()``` makes cylinders that fit inside a round hole. Layers that are less than 2 filaments wide and layers that need more than a 45 degree overhang are omitted.
+
 
 [utils/horiholes.scad](utils/horiholes.scad) Implementation.
 
@@ -5369,11 +5399,13 @@ Utilities for depicting the staircase slicing of horizontal holes made with [`te
 ### Functions
 | Function | Description |
 |:--- |:--- |
+| ```teardrop_minus_x(r, y, h)``` | Calculate the ordinate of a compensated teardrop given y and layer height. |
 | ```teardrop_plus_x(r, y, h)``` | Calculate the ordinate of a compensated teardrop given y and layer height. |
 
 ### Modules
 | Module | Description |
 |:--- |:--- |
+| ```horicylinder(r, z, h = 0, center = true)``` | For making horizontal cylinders that don't need support material and are correct dimensions |
 | ```horihole(r, z, h = 0, center = true)``` | For making horizontal holes that don't need support material and are correct dimensions |
 
 ![horiholes](tests/png/horiholes.png)
@@ -5420,7 +5452,14 @@ Maths utilities for manipulating vectors and matrices.
 | Function | Description |
 |:--- |:--- |
 | ```angle_between(v1, v2)``` | Return the angle between two vectors |
+| ```argcosh(x)``` | inverse hyperbolic cosine |
+| ```argcoth(x)``` | inverse hyperbolic cotangent |
+| ```argsinh(x)``` | inverse hyperbolic sine |
+| ```argtanh(x)``` | inverse hyperbolic tangent |
 | ```augment(m)``` | Augment a matrix by adding an identity matrix to the right |
+| ```circle_intersect(c1, r1, c2, r2)``` | Calculate one point where two circles in the X-Z plane intersect, clockwise around c1 |
+| ```cosh(x)``` | hyperbolic cosine |
+| ```coth(x)``` | hyperbolic cotangent |
 | ```degrees(radians)``` | Convert degrees to radians |
 | ```euler(R)``` | Convert a rotation matrix to a Euler rotation vector. |
 | ```identity(n, x = 1)``` | Construct an arbitrary size identity matrix |
@@ -5433,9 +5472,11 @@ Maths utilities for manipulating vectors and matrices.
 | ```rotate(a, v)``` | Generate a 4x4 rotation matrix, ```a``` can be a vector of three angles or a single angle around ```z```, or around axis ```v``` |
 | ```rowswap(m, i, j)``` | Swap two rows of a matrix |
 | ```scale(v)``` |  Generate a 4x4 matrix that scales by ```v```, which can be a vector of xyz factors or a scalar to scale all axes equally |
+| ```sinh(x)``` | hyperbolic sine |
 | ```solve(m, i = 0, j = 0)``` | Solve each row ensuring diagonal is not zero |
 | ```solve_row(m, i)``` | Make diagonal one by dividing the row by it and subtract from other rows to make column zero |
 | ```sqr(x)``` | Square x |
+| ```tanh(x)``` | hyperbolic tangent |
 | ```transform(v, m)``` | Apply 4x4 transform to a 3 vector by extending it and cropping it again |
 | ```transform_points(path, m)``` | Apply transform to a path |
 | ```translate(v)``` | Generate a 4x4 translation matrix, ```v``` can be ```[x, y]```, ```[x, y, z]``` or ```z``` |
@@ -5625,7 +5666,7 @@ An additional twist around the path can be specified. If the path is closed this
 ### Modules
 | Module | Description |
 |:--- |:--- |
-| ```sweep(path, profile, loop = false, twist = 0)``` | Draw a polyhedron that is the swept volume |
+| ```sweep(path, profile, loop = false, twist = 0, convexity = 1)``` | Draw a polyhedron that is the swept volume |
 
 ![sweep](tests/png/sweep.png)
 
@@ -5817,11 +5858,13 @@ Global constants, functions and modules. This file is used directly or indirectl
 | ```foot(x)``` | Foot to mm conversion |
 | ```in(list, x)``` | Returns true if ```x``` is an element in the ```list``` |
 | ```inch(x)``` | Inch to mm conversion (For fractional inches, 'inch(1 + 7/8)' will work as expected.) |
+| ```limit(x, min, max)``` | Force x in range min <= x <= max |
 | ```m(x)``` | m to mm conversion |
 | ```mm(x)``` | Explicit mm specified |
 | ```no_point(str)``` | Replace decimal point in string with 'p' |
 | ```r2sides(r)``` | Replicates the OpenSCAD logic to calculate the number of sides from the radius |
 | ```r2sides4n(r)``` | Round up the number of sides to a multiple of 4 to ensure points land on all axes |
+| ```slice(list, start = 0, end = undef)``` | Slice a list or string with Python type semantics |
 | ```sqr(x)``` | Returns the square of ```x``` |
 | ```yard(x)``` | Yard to mm conversion |
 

scripts/tests.py

@@ -97,7 +97,6 @@ def tests(tests):
     for dir in [deps_dir, png_dir, bom_dir]:
         if not os.path.isdir(dir):
             os.makedirs(dir)
-    doc_name = "readme.md"
     index = {}
     bodies = {}
     done = []
@@ -108,19 +107,33 @@ def tests(tests):
     #
     png_name = "libtest.png"
     scad_name = "libtest.scad"
-    if not os.path.isfile(png_name):
-        openscad.run(colour_scheme, "--projection=p", "--imgsize=%d,%d" % (w, h), "--camera=0,0,0,50,0,340,500", "--autocenter", "--viewall", "-o", png_name, scad_name);
-        do_cmd(["magick", png_name, "-trim", "-resize", "1280", "-bordercolor", background, "-border", "10", png_name])
+    if os.path.isfile(scad_name):
+        libtest = True
+        lib_blurb = scrape_blurb(scad_name)
+        if not os.path.isfile(png_name):
+            openscad.run(colour_scheme, "--projection=p", "--imgsize=%d,%d" % (w, h), "--camera=0,0,0,50,0,340,500", "--autocenter", "--viewall", "-o", png_name, scad_name);
+            do_cmd(["magick", png_name, "-trim", "-resize", "1280", "-bordercolor", background, "-border", "10", png_name])
+    else:
+        #
+        # Project tests so just a title
+        #
+        libtest = False
+        project = ' '.join(word[0].upper() + word[1:] for word in os.path.basename(os.getcwd()).split('_'))
+        lib_blurb = '#' + project + ' Tests\n'
+
+    doc_base_name = "readme" if libtest else "tests"
+    doc_name = doc_base_name + ".md"
     #
     # List of individual part files
     #
-    scads = [i for i in sorted(os.listdir(scad_dir), key = lambda s: s.lower()) if i[-5:] == ".scad"]
 
+    scads = [i for i in sorted(os.listdir(scad_dir), key = lambda s: s.lower()) if i[-5:] == ".scad"]
+    types = []
     for scad in scads:
         base_name = scad[:-5]
         if not tests or base_name in tests:
             done.append(base_name)
-            print(base_name)
+            print('\n'+base_name)
             cap_name = base_name[0].capitalize() + base_name[1:]
             base_name = base_name.lower()
             scad_name = scad_dir + '/' + scad
@@ -132,29 +145,42 @@ def tests(tests):
             if is_plural(base_name) and os.path.isfile(vits_name):
                 objects_name = vits_name
 
-            locations = [
-                ('vitamins/' + depluralise(base_name) + '.scad', 'Vitamins'),
-                ('printed/' + base_name + '.scad',               'Printed'),
-                ('utils/' + base_name + '.scad',                 'Utilities'),
-                ('utils/core/' + base_name + '.scad',            'Core Utilities'),
-            ]
+            locations = []
+            if os.path.isdir('vitamins'):
+                locations.append(('vitamins/' + depluralise(base_name) + '.scad', 'Vitamins'))
+            if os.path.isdir('printed'):
+                locations.append(('printed/' + base_name + '.scad',               'Printed'))
+            if os.path.isdir('utils'):
+                locations.append(('utils/' + base_name + '.scad',                 'Utilities'))
+            if libtest and os.path.isdir('utils/core'):
+                locations.append(('utils/core/' + base_name + '.scad',            'Core Utilities'))
 
             for name, type in locations:
                 if os.path.isfile(name):
                     impl_name = name
                     break
             else:
-                print("Can't find implementation!")
-                continue
+                if libtest:
+                    print("Can't find implementation!")
+                    continue
+                else:
+                    type = 'Tests'                         # OK when testing part of a project
+                    impl_name = None
 
-            vsplit = "AJR" + chr(ord('Z') + 1)
-            vtype = locations[0][1]
-            types = [vtype + ' ' + vsplit[i] + '-'  + chr(ord(vsplit[i + 1]) - 1) for i in range(len(vsplit) - 1)] + [loc[1] for loc in locations[1 :]]
-            if type == vtype:
-                for i in range(1, len(vsplit)):
-                    if cap_name[0] < vsplit[i]:
-                         type = types[i - 1]
-                         break
+            if libtest:
+                vsplit = "AJR" + chr(ord('Z') + 1)
+                vtype = locations[0][1]
+                types = [vtype + ' ' + vsplit[i] + '-' + chr(ord(vsplit[i + 1]) - 1) for i in range(len(vsplit) - 1)] + [loc[1] for loc in locations[1 :]]
+                if type == vtype:
+                    for i in range(1, len(vsplit)):
+                        if cap_name[0] < vsplit[i]:
+                             type = types[i - 1]
+                             break
+            else:
+                if not types:
+                    types = [loc[1] for loc in locations]   # No need to split up the vitamin list
+                    if not type in types:                   # Will happen when implementation is not found and type is set to Tests
+                        types.append(type)
 
             for t in types:
                 if not t in bodies:
@@ -250,24 +276,7 @@ def tests(tests):
         usage()
 
     with open(doc_name, "wt") as doc_file:
-        print('# NopSCADlib', file = doc_file)
-        print('''\
-An ever expanding library of parts modelled in OpenSCAD useful for 3D printers and enclosures for electronics, etc.
-
-It contains lots of vitamins (the RepRap term for non-printed parts), some general purpose printed parts and
-some utilities. There are also Python scripts to generate Bills of Materials (BOMs),
- STL files for all the printed parts, DXF files for CNC routed parts in a project and a manual containing assembly
-instructions and exploded views by scraping markdown embedded in OpenSCAD comments, [see scripts](scripts/readme.md). A simple example project can be found [here](examples/MainsBreakOutBox/readme.md).
-
-For more examples of what it can make see the [gallery](gallery/readme.md).
-
-The license is GNU General Public License v3.0, see [COPYING](COPYING).
-
-See [usage](docs/usage.md) for requirements, installation instructions and a usage guide.
-
-<img src="libtest.png" width="100%"/>\n
-''', file = doc_file)
-
+        print(lib_blurb, file = doc_file)
         print('## Table of Contents<a name="top"/>', file = doc_file)
         print('<table><tr>', file = doc_file)
         n = 0
@@ -288,10 +297,10 @@ See [usage](docs/usage.md) for requirements, installation instructions and a usa
         for type in types:
             for line in bodies[type]:
                 print(line, file = doc_file)
-    with open("readme.html", "wt") as html_file:
-        do_cmd("python -m markdown -x tables readme.md".split(), html_file)
+    with open(doc_base_name + ".html", "wt") as html_file:
+        do_cmd(("python -m markdown -x tables " + doc_name).split(), html_file)
     times.print_times()
-    do_cmd('codespell -L od readme.md'.split())
+    do_cmd(('codespell -L od ' + doc_name).split())
 
 if __name__ == '__main__':
     for arg in sys.argv[1:]:

tests/catenary.scad

@@ -0,0 +1,56 @@
+//
+// NopSCADlib Copyright Chris Palmer 2020
+// nop.head@gmail.com
+// hydraraptor.blogspot.com
+//
+// This file is part of NopSCADlib.
+//
+// NopSCADlib is free software: you can redistribute it and/or modify it under the terms of the
+// GNU General Public License as published by the Free Software Foundation, either version 3 of
+// the License, or (at your option) any later version.
+//
+// NopSCADlib is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+// without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+// See the GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along with NopSCADlib.
+// If not, see <https://www.gnu.org/licenses/>.
+//
+l = 250; // [1: 1000]
+x = 200; // [1: 1000]
+y = 50; //[-500 : 500]
+
+include <../utils/core/core.scad>
+use <../utils/catenary.scad>
+use <../utils/sweep.scad>
+use <../utils/annotation.scad>
+
+module catenaries() {
+    //
+    // catenary curve path from control points
+    //
+    curve = [for(p = catenary_points(l, x, y)) [p.x, p.y, 0]];
+    //
+    // Draw the curve
+    //
+    r = 0.5;
+    sweep(curve, circle_points(r, $fn = 64));
+    //
+    // Minimum Z
+    //
+    min_z = catenary_points(l, x, y, 0);
+
+    color("blue") {
+        translate([min_z.x, min_z.y + r])
+            rotate([-90, 0, 0])
+                arrow();
+
+        translate([min_z.x, min_z.y - r])
+            rotate([90, 0, 0])
+                arrow();
+    }
+}
+
+if($preview)
+    rotate(is_undef($bom) ? 0 : [70, 0, 315])
+        catenaries();

tests/global.scad

@@ -29,6 +29,23 @@ module globals() {
         translate([50, 0])
             right_triangle(10, 20, 0);
     }
+    assert(slice("ABCD")    == "ABCD");
+    assert(slice("ABCD", 1) == "BCD");
+    assert(slice("ABCD", 2) == "CD");
+    assert(slice("ABCD", 3) == "D");
+    assert(slice("ABCD", 4) == "");
+    assert(slice("ABCD", 1, -1) == "BC");
+    assert(slice("ABCD", 2, -1) == "C");
+    assert(slice("ABCD", 3, -1) == "");
+    assert(slice("ABCD", 4, -1) == "");
+    assert(slice("ABCD", 0, -1) == "ABC");
+    assert(slice("ABCD", 0, -2) == "AB");
+    assert(slice("ABCD", 0, -3) == "A");
+    assert(slice("ABCD", 0, -4) == "");
+    assert(slice("ABCD", 0,  0) == "");
+    assert(slice("ABCD", 0,  1) == "A");
+    assert(slice("ABCD", 0,  2) == "AB");
+    assert(slice("ABCD", 0,  3) == "ABC");
 }
 
 rotate([70, 0, 315]) globals();

tests/horiholes.scad

@@ -69,9 +69,13 @@ module horiholes() {
             color(silver)
                 cylinder(r = $r, h = eps, center = true, $fn = 360);
 
+    hole_positions()
+        color("blue")
+            horicylinder(r = $r, z = $z, h = 2 * eps, center = true, $fn = 360);
+
     hole_positions()
         color("red")
-            linear_extrude(2 * eps, center = true)
+            linear_extrude(3 * eps, center = true)
                 intersection() {
                     difference() {
                         square(8, center = true);

tests/maths.scad

@@ -69,6 +69,33 @@ module maths() {
     // Test Euler
     //
     assert(euler(rotate(r)) == r, "euler() failed");
+    //
+    // Circle intersect
+    //
+    r1 = 10;
+    c1 = [50, 0, 10];
+    r2 = 20;
+    c2 = [67, 0, 0];
+    p1 = circle_intersect(c1, r1, c2, r2);
+    p2 = circle_intersect(c2, r2, c1, r1);
+
+    rotate(90) {
+        color(grey(90))
+            translate(c1) rotate([90, 0, 0]) cylinder(r = r1, h = 4 * eps, center = true);
+
+        color(grey(80))
+            translate(c2) rotate([90, 0, 0]) cylinder(r = r2, h = eps, center = true);
+
+        color("red")
+            translate(p1) rotate([90, 0, 0]) cylinder(r = 0.1, h = 6 * eps, center = true);
+
+        color("blue")
+            translate(p2) rotate([90, 0, 0]) cylinder(r = 0.1, h = 6 * eps, center = true);
+
+        translate(p1) arrow();
+
+        translate(p2) vflip() arrow();
+    }
 }
 
 rotate(45)

tests/stepper_motors.scad

@@ -24,7 +24,7 @@ use <../utils/layout.scad>
 module stepper_motors()
     layout([for(s = stepper_motors) NEMA_width(s)], 5) {
         rotate(180)
-            NEMA(stepper_motors[$i]);
+            NEMA(stepper_motors[$i], 0, $i > 1 && $i < 5);
 
         translate_z(4)
             NEMA_screws(stepper_motors[$i], M3_pan_screw, n = $i, earth = $i > 4 ? undef : $i - 1);

utils/catenary.scad

@@ -0,0 +1,52 @@
+//
+// NopSCADlib Copyright Chris Palmer 2020
+// nop.head@gmail.com
+// hydraraptor.blogspot.com
+//
+// This file is part of NopSCADlib.
+//
+// NopSCADlib is free software: you can redistribute it and/or modify it under the terms of the
+// GNU General Public License as published by the Free Software Foundation, either version 3 of
+// the License, or (at your option) any later version.
+//
+// NopSCADlib is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
+// without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+// See the GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along with NopSCADlib.
+// If not, see <https://www.gnu.org/licenses/>.
+//
+
+//
+//! Catenary curve to model hanging wires, etc.
+//!
+//! Although the equation of the curve is simply ```y = a cosh(x / a)``` there is no explicit formula to calculate the constant ```a``` or the range of ```x``` given the
+//! length of the cable and the end point coordinates. See <https://en.wikipedia.org/wiki/Catenary#Determining_parameters>. The Newton-Raphson method is used to find
+//! ```a``` numerically, see <https://en.wikipedia.org/wiki/Newton%27s_method>.
+//!
+//! The coordinates of the lowest point on the curve can be retrieved by calling ```catenary_points()``` with ```steps``` equal to zero.
+//
+include <core/core.scad>
+use <maths.scad>
+
+function catenary(t, a) = let(u = argsinh(t)) a * [u, cosh(u)]; //! Parametric catenary function linear along the length of the curve.
+function catenary_s(d, a) = 2 * a * sinh(d / a); //! Length of a symmetric catenary with width ```2d```.
+function catenary_ds_by_da(d, a) = 2 * sinh(d / a) - 2 * d / a * cosh(d / a); //! First derivative of the length with respect to ```a```.
+
+function catenary_find_a(d, l, a = 1, best_e = inf, best_a = 1) =  //! Find the catenary constant ```a```, given half the horizontal span and the length.
+     assert(l > 2 * d, "Not long enough to span the gap") assert(d) let(error = abs(catenary_s(d, a) - l))
+     error >= best_e && error < 0.0001 ? best_a
+                                       : catenary_find_a(d, l, max(a - (catenary_s(d, a) - l) / catenary_ds_by_da(d, a), d / argsinh(1e99)), error, a);
+
+function catenary_points(l, x, y, steps = 100) = //! Returns a list of 2D points on the curve that goes from the origin to ```(x,y)``` and has length ```l```.
+    let(
+        d = x / 2,
+        a = catenary_find_a(d, sqrt(sqr(l) - sqr(y))),   // Find a to get the correct length
+        offset = argsinh(y / catenary_s(d, a)),
+        t0 = sinh(-d / a + offset),
+        t1 = sinh( d / a + offset),
+        h = a * cosh(-d / a + offset) - a,
+        lowest = offset > d / a ? [0, 0] : offset < -d / a ? [x, y] : [d - offset * a, -h],
+        p0 = catenary(t0, a)
+    )
+    steps ? [for(t = [t0 : (t1 - t0) / steps : t1]) catenary(t, a) - p0] : lowest;

utils/core/core.scad

@@ -18,7 +18,7 @@
 //
 
 //
-// Include this file to use the miniumum library
+// Include this file to use the minimum library
 //
 include <../../global_defs.scad>
 //

utils/core/global.scad

@@ -36,12 +36,22 @@ function in(list, x) = !!len([for(v = list) if(v == x) true]);
 function Len(x) = is_list(x) ? len(x) : 0;                                          //! Returns the length of a list or 0 if ```x``` is not a list
 function r2sides(r) = $fn ? $fn : ceil(max(min(360/ $fa, r * 2 * PI / $fs), 5));    //! Replicates the OpenSCAD logic to calculate the number of sides from the radius
 function r2sides4n(r) = floor((r2sides(r) + 3) / 4) * 4;                            //! Round up the number of sides to a multiple of 4 to ensure points land on all axes
+function limit(x, min, max) = max(min(x, max), min);                                //! Force x in range min <= x <= max
 
 module translate_z(z) translate([0, 0, z]) children();                              //! Shortcut for Z only translations
 module vflip() rotate([180, 0, 0]) children();                                      //! Invert children by doing a 180&deg; flip around the X axis
 module hflip() rotate([0, 180, 0]) children();                                      //! Invert children by doing a 180&deg; flip around the Y axis
 module ellipse(xr, yr) scale([1, yr / xr]) circle4n(xr);                            //! Draw an ellipse
 
+function slice_str(str, start, end, s ="") = start >= end ? s : slice_str(str, start + 1, end, str(s, str[start])); // Helper for slice()
+
+function slice(list, start = 0, end = undef) = let( //! Slice a list or string with Python type semantics
+        len = len(list),
+        start = limit(start < 0 ? len + start : start, 0, len),
+        end   = is_undef(end) ? len : limit(end   < 0 ? len + end : end, 0, len)
+    ) is_string(list) ? slice_str(list, start, end) : [for(i = [start : 1 : end - 1]) list[i]];
+
+
 module extrude_if(h, center = true)                 //! Extrudes 2D object to 3D when ```h``` is nonzero, otherwise leaves it 2D
     if(h)
         linear_extrude(h, center = center, convexity = 2) // 3D

utils/horiholes.scad

@@ -19,6 +19,8 @@
 
 //
 //! Utilities for depicting the staircase slicing of horizontal holes made with [`teardrop_plus()`](#teardrops), see <https://hydraraptor.blogspot.com/2020/07/horiholes-2.html>
+//!
+//! ```horicylinder()``` makes cylinders that fit inside a round hole. Layers that are less than 2 filaments wide and layers that need more than a 45 degree overhang are omitted.
 //
 include <../utils/core/core.scad>
 
@@ -53,3 +55,29 @@ module horihole(r, z, h = 0, center = true) { //! For making horizontal holes th
                         }
              }
 }
+
+function teardrop_minus_x(r, y, h) = //! Calculate the ordinate of a compensated teardrop given y and layer height.
+    let(fr = h / 2,
+        hpot = r - fr,
+        x2 = sqr(hpot) - sqr(y),
+        x = x2 > 0 ? sqrt(x2) : 0,
+        X = y >= -hpot / sqrt(2) ? x + fr : 0
+    )
+    X >= extrusion_width ? X : 0;
+
+module horicylinder(r, z, h = 0, center = true) { //! For making horizontal cylinders that don't need support material and are correct dimensions
+    bot_layer = floor((z - r) / layer_height);
+    top_layer = ceil((z + r) / layer_height);
+    render(convexity = 5)
+        extrude_if(h, center)
+            for(i = [bot_layer : top_layer]) {
+                Z = i * layer_height;
+                y = Z - z + layer_height / 2;
+                x = teardrop_minus_x(r, y, layer_height);
+                if(x >= extrusion_width)
+                    hull()
+                        for(end = [-1, 1])
+                            translate([end * (x - layer_height / 2), y])
+                                circle(d = layer_height, $fn = 32);
+             }
+}

utils/maths.scad

@@ -24,6 +24,14 @@ function sqr(x) = x * x;                        //! Square x
 function radians(degrees) = degrees * PI / 180; //! Convert radians to degrees
 function degrees(radians) = radians * 180 / PI; //! Convert degrees to radians
 
+function sinh(x) = (exp(x) - exp(-x)) / 2;      //! hyperbolic sine
+function cosh(x) = (exp(x) + exp(-x)) / 2;      //! hyperbolic cosine
+function tanh(x) = sinh(x) / cosh(x);           //! hyperbolic tangent
+function coth(x) = cosh(x) / sinh(x);           //! hyperbolic cotangent
+function argsinh(x) = ln(x + sqrt(sqr(x) + 1)); //! inverse hyperbolic sine
+function argcosh(x) = ln(x + sqrt(sqr(x) - 1)); //! inverse hyperbolic cosine
+function argtanh(x) = ln((1 + x) / (1 - x)) / 2;//! inverse hyperbolic tangent
+function argcoth(x) = ln((x + 1) / (x - 1)) / 2;//! inverse hyperbolic cotangent
 
 function translate(v) = let(u = is_list(v) ? len(v) == 2 ? [v.x, v.y, 0] //! Generate a 4x4 translation matrix, ```v``` can be ```[x, y]```, ```[x, y, z]``` or ```z```
                                                          : v
@@ -138,3 +146,10 @@ function invert(m) = let(n =len(m), m = solve(augment(m))) [ //! Invert a matrix
              each m[i][j]
     ]
 ];
+
+function circle_intersect(c1, r1, c2, r2) =     //! Calculate one point where two circles in the X-Z plane intersect, clockwise around c1
+    let(
+        v = c1 - c2,                            // Line between centres
+        d = norm(v),                            // Distance between centres
+        a = atan2(v.z, v.x) - acos((sqr(d) + sqr(r2) - sqr(r1)) / (2 * d * r2)) // Cosine rule to find angle from c2
+     ) c2 + r2 * [cos(a), 0, sin(a)];           // Point on second circle

utils/sweep.scad

@@ -34,14 +34,22 @@ function transpose3(m) = [ [m[0].x, m[1].x, m[2].x],
                            [m[0].y, m[1].y, m[2].y],
                            [m[0].z, m[1].z, m[2].z] ];
 //
+// Find the first non-colinear point
+//
+tiny = 0.00001;
+function find_curve(tangents, i = 1) =
+    i >= len(tangents) - 1 || norm(cross(tangents[0], tangents[i] - tangents[0])) > tiny ? i
+                                                                                         : find_curve(tangents, i + 1);
+//
 // Frenet-Serret frame
 //
 function fs_frame(tangents) =
     let(tangent = tangents[0],
-        normal = tangents[1] - tangents[0],
+        i = find_curve(tangents),
+        normal = tangents[i] - tangents[0],
         binormal = cross(tangent, normal),
         z = unit(tangent),
-        x = assert(norm(binormal) > 0.00001, "first three points are colinear") unit(binormal),
+        x = assert(norm(binormal) > tiny, "all points are colinear") unit(binormal),
         y = unit(cross(z, x))
        ) [[x.x, y.x, z.x],
           [x.y, y.y, z.y],
@@ -70,7 +78,6 @@ function orientate(p, r) =
          [x.y, y.y, z.y],
          [x.z, y.z, z.z],
          [p.x, p.y, p.z]];
-
 //
 // Rotate around z
 //
@@ -145,10 +152,10 @@ function sweep(path, profile, loop = false, twist = 0) = //! Generate the point
         faces = loop ? skin_faces : concat([cap(facets)], skin_faces, [cap(facets, npoints - 1)])
         ) [points, faces];
 
-module sweep(path, profile, loop = false, twist = 0) { //! Draw a polyhedron that is the swept volume
+module sweep(path, profile, loop = false, twist = 0, convexity = 1) { //! Draw a polyhedron that is the swept volume
     mesh = sweep(path, profile, loop, twist);
 
-    polyhedron(points = mesh[0], faces = mesh[1]);
+    polyhedron(points = mesh[0], faces = mesh[1], convexity = convexity);
 }
 
 function path_length(path, i = 0, length = 0) = //! Calculated the length along a path

vitamins/cable_strip.scad

@@ -20,7 +20,7 @@
 //
 //! A strip of polypropylene used with ribbon cable to make a cable flexible in one direction only.
 //!
-//! Modelled with a Bezier spline, which is not quite the same as a miniumum energy curve but very close, epecially
+//! Modelled with a Bezier spline, which is not quite the same as a minimum energy curve but very close, epecially
 //! near the extreme positions, where the model needs to be accurate.
 //!
 //! When the sides are constrained then a circular model is more accurate.

vitamins/component.scad

@@ -161,13 +161,13 @@ module al_clad_resistor(type, value, leads = true) { //! Draw an aluminium clad
                 }
         linear_extrude(thickness)
             difference() {
-                for(end = [-1, 1])
-                    translate([end * (length - tab) / 2, end * (width - width / 2) / 2])
-                        square([tab, width / 2], center = true);
+                union()
+                    for(end = [-1, 1])
+                        translate([end * (length - tab) / 2, end * (width - width / 2) / 2])
+                            square([tab, width / 2], center = true);
 
                 al_clad_resistor_hole_positions(type)
                     circle(d = al_clad_hole(type));
-
             }
         if(leads) {
             translate_z(height / 2)

vitamins/insert.scad

@@ -137,19 +137,26 @@ module insert_lug(insert, wall, counter_bore = 0, extension = 0, corner_r = 0, f
     boss_h = insert_hole_length(insert);
     boss_h2 = boss_h + counter_bore;
 
-    module shape()
-        intersection() {
+    module shape() {
+        module _shape()
             hull() {
                 circle(boss_r);
 
                 translate([boss_r + extension - eps, 0])
                     square([eps, 2 * boss_r], center = true);
             }
-            if(corner_r)
+
+        if(corner_r)
+            intersection() {
+                _shape();
+
                 translate([boss_r + extension - corner_r, 0])
                     rotate(-45)
                         quadrant(w = 100, r = corner_r - eps, center = true);
-        }
+            }
+        else
+            _shape();
+    }
 
     translate_z(-boss_h)
         linear_extrude(boss_h)

vitamins/jhead.scad

@@ -179,23 +179,27 @@ module jhead_hot_end_assembly(type, filament, naked = false) { //! Assembly with
     //
     // heater block
     //
-    rotate(90)
-        translate([-nozzle_x(heater), 0, inset - insulator_length - heater_height(heater) / 2]) {
-            intersection() {
-                group() {
-                    translate([resistor_x(heater), -exploded() * 15, 0])
-                        rotate([90, 0, 0])
-                             sleeved_resistor(resistor, PTFE20, bare = -10);
+    module heater_components() {
+        translate([resistor_x(heater), -exploded() * 15, 0])
+            rotate([90, 0, 0])
+                 sleeved_resistor(resistor, PTFE20, bare = -10);
+
+        translate([-heater_length(heater) / 2 + resistor_length(thermistor) / 2 - exploded() * 10, thermistor_y(heater), 0])
+            rotate([90, 0, -90])
+                 sleeved_resistor(thermistor, PTFE07, heatshrink = HSHRNK16);
+    }
+
+    rotate(90)
+        translate([-nozzle_x(heater), 0, inset - insulator_length - heater_height(heater) / 2])
+            if(exploded())
+                heater_components();
+            else
+                intersection() {
+                    heater_components();
 
-                    translate([-heater_length(heater) / 2 + resistor_length(thermistor) / 2 - exploded() * 10, thermistor_y(heater), 0])
-                        rotate([90, 0, -90])
-                             sleeved_resistor(thermistor, PTFE07, heatshrink = HSHRNK16);
-                }
-                if(!exploded())
                     if(naked)
                         color("grey") cylinder(r = 12, h = 100, center = true);
                     else
                         cube(1, true);             // hide the wires when not exploded
-            }
-    }
+                }
 }

vitamins/panel_meter.scad

@@ -77,7 +77,6 @@ module panel_meter(type) { //! Draw panel mounted LCD meter module
     tab_z = pmeter_tab_z(type);
     pcb = pmeter_pcb(type);
     ap2 = pmeter_inner_ap(type);
-    pcb_h = pmeter_pcb_h(type) - bezel.z;
     buttons = pmeter_buttons(type);
 
     color("#94A7AB")
@@ -146,15 +145,16 @@ module panel_meter(type) { //! Draw panel mounted LCD meter module
                     translate(pmeter_inner_ap_o(type))
                         square([ap2.x, ap2.y], center = true);
                 }
-    if(pcb)
+    if(pcb) {
         vflip()
             translate_z(h - pcb_thickness(pcb) - pmeter_pcb_z(type))
                 pcb(pcb);
 
-    if(pcb_h > 0)
-        %translate_z(-pcb_h / 2 - eps)
-            cube([size.x - 2 * t - eps, size.y - 2 * t - eps, pcb_h], center = true);
-
+        pcb_h = pmeter_pcb_h(type) - bezel.z;
+        if(pcb_h > 0)
+            %translate_z(-pcb_h / 2 - eps)
+                cube([size.x - 2 * t - eps, size.y - 2 * t - eps, pcb_h], center = true);
+    }
     if(buttons)
         for(b = buttons)
             panel_meter_button(b);

vitamins/panel_meters.scad

@@ -44,7 +44,7 @@ DSP5005   = ["DSP5005", "Ruideng DSP5005 Power supply module",                [7
 DSN_VC288PCB = ["", "", 41, 21, 1, 0, 0, 0, "green", false, [], [[ 5,  -3,   0, "jst_xh", 3], ], []];
 
 DSN_VC288 = ["DSN_VC288","DSN-VC288 DC 100V 10A Voltmeter ammeter",            [45.3, 26,   17.4], [47.8, 28.8, 2.5], 0,   [1, 1.8], [36, 18, 2.5], [],            0, 2,
-              [], 0, DSN_VC288PCB, 5];
+              [], 0, DSN_VC288PCB, 5, 0];
 
 panel_meters = [DSN_VC288, PZEM021, PZEM001, DSP5005];
 

vitamins/pcbs.scad

@@ -385,6 +385,11 @@ WD2002SJ = ["WD2002SJ", "WD2002SJ Buck Boost DC-DC converter", 78, 47, 1.6, 0, 3
     ],
     []];
 
+MP1584EN = ["MP1584EN", "MP1584EN 3A buck converter", 22, 17, 1.2, 0, 1, [2, 2], "green", false,
+    [[1.75, 1.75], [1.75, -1.75], [-1.75, 1.75], [-1.75, -1.75], [-1.75, -4.4], [-1.75, 4.48], [1.75, -4.4], [1.75, 4.4]],
+    []
+];
+
 PERF80x20 = ["PERF80x20", "Perfboard 80 x 20mm", 80, 20, 1.6, 0, 2.3, 0, "green", true, [[2,2],[-2,2],[2,-2],[-2,-2]], [], [], [5.87, 3.49]];
 
 PERF70x50 = ["PERF70x50", "Perfboard 70 x 50mm", 70, 50, 1.6, 0, 2.3, 0, "green", true, [[2,2],[-2,2],[2,-2],[-2,-2]], [], [], [5.87, 3.49]];
@@ -410,7 +415,7 @@ RAMPSEndstop = ["RAMPSEndstop", "RAMPS Endstop Switch",
     []];
 
 
-pcbs = [TP4056, MT3608, RAMPSEndstop, ExtruderPCB, PI_IO, ZC_A0591, RPI0, EnviroPlus, ArduinoUno3, ArduinoLeonardo, Keyes5p1, PSU12V1A, WD2002SJ, RPI3, RPI4, DuetE, Duex2, Duex5, Melzi];
+pcbs = [MP1584EN, TP4056, MT3608, RAMPSEndstop, ExtruderPCB, PI_IO, ZC_A0591, RPI0, EnviroPlus, ArduinoUno3, ArduinoLeonardo, Keyes5p1, PSU12V1A, WD2002SJ, RPI3, RPI4, DuetE, Duex2, Duex5];
 
 perfboards = [PERF74x51, PERF70x50, PERF60x40, PERF70x30, PERF80x20];
 

vitamins/smd.scad

@@ -62,9 +62,10 @@ module smd_led(type, colour, cutout) { //! Draw an SMD LED with specified ```col
                 intersection() {
                     square([size.x, size.y], center = true);
 
-                    for(end = [-1, 1])
-                        translate([end * size.x / 2, 0])
-                            ring(or = r, ir = r / 2);
+                    union()
+                        for(end = [-1, 1])
+                            translate([end * size.x / 2, 0])
+                                ring(or = r, ir = r / 2);
                 }
 
         color(colour, 0.9)

vitamins/stepper_motor.scad

@@ -23,6 +23,7 @@
 include <../core.scad>
 include <ring_terminals.scad>
 
+include <../vitamins/pin_headers.scad>
 use <../utils/tube.scad>
 use <../utils/thread.scad>
 use <washer.scad>
@@ -39,7 +40,6 @@ function NEMA_shaft_length(type)= type[8]; //! Shaft length above the face, if a
 function NEMA_hole_pitch(type)  = type[9]; //! Screw hole pitch
 function NEMA_holes(type)       = [-NEMA_hole_pitch(type) / 2, NEMA_hole_pitch(type) / 2]; //! Screw positions for for loop
 function NEMA_big_hole(type)    = NEMA_boss_radius(type) + 0.2; //! Clearance hole for the big boss
-
 stepper_body_colour = "black";
 stepper_cap_colour  = grey(50);
 stepper_machined_colour = grey(90);
@@ -52,7 +52,7 @@ module NEMA_outline(type) //! 2D outline
         circle(NEMA_radius(type));
     }
 
-module NEMA(type, shaft_angle = 0) { //! Draw specified NEMA stepper motor
+module NEMA(type, shaft_angle = 0, jst_connector = false) { //! Draw specified NEMA stepper motor
     side = NEMA_width(type);
     length = NEMA_length(type);
     body_rad = NEMA_body_radius(type);
@@ -89,15 +89,26 @@ module NEMA(type, shaft_angle = 0) { //! Draw specified NEMA stepper motor
         tube(or = boss_rad, ir =  shaft_rad + 2, h = boss_height * 2); // raised boss
 
         linear_extrude(eps)
-            cap_shape(true);
+            cap_shape(1);
     }
 
-    color(stepper_cap_colour)                                       // aluminium end caps
+    tabSize = [16, 4, 2.5];
+    color(stepper_cap_colour) {                                     // aluminium end caps
         for(end = [-1, 1])
             translate_z(-length / 2 + end * (length - cap) / 2)
                 linear_extrude(cap, center = true)
                     cap_shape(end);
 
+        if(jst_connector)
+            translate([-tabSize.x / 2, side / 2, -length])
+                cube(tabSize);
+    }
+
+    if(jst_connector)
+        translate([0, side / 2 - 2, -length + tabSize.z + 5.75 / 2])
+            rotate([-90, 0, 0])
+                jst_xh_header(jst_xh_header, 6);
+
     if(show_threads)
         for(x = NEMA_holes(type), y = NEMA_holes(type))
             translate([x, y, -cap / 2])
@@ -111,15 +122,16 @@ module NEMA(type, shaft_angle = 0) { //! Draw specified NEMA stepper motor
                     cylinder(r = shaft_rad, h = shaft + 5);  // shaft
             else
                 not_on_bom()
-                    leadscrew(shaft_rad * 2, shaft.x + 5, shaft.y, shaft.z, center = false)
+                    leadscrew(shaft_rad * 2, shaft.x + 5, shaft.y, shaft.z, center = false);
 
-    translate([0, side / 2, -length + cap / 2])
-        rotate([90, 0, 0])
-            for(i = [0 : 3])
-                rotate(225 + i * 90)
-                    color(["red", "blue","green","black"][i])
-                        translate([1, 0, 0])
-                            cylinder(r = 1.5 / 2, h = 12, center = true);
+    if(!jst_connector)
+        translate([0, side / 2, -length + cap / 2])
+            rotate([90, 0, 0])
+                for(i = [0 : 3])
+                    rotate(225 + i * 90)
+                        color(["red", "blue","green","black"][i])
+                            translate([1, 0, 0])
+                                cylinder(r = 1.5 / 2, h = 12, center = true);
 }
 
 module NEMA_screw_positions(type, n = 4) { //! Positions children at the screw holes

vitamins/stepper_motors.scad

@@ -23,13 +23,13 @@
 
 //                                   corner  body    boss    boss          shaft
 //                     side, length, radius, radius, radius, depth, shaft, length,      holes
-NEMA17  = ["NEMA17",   42.3, 47,     53.6/2, 25,     11,     2,     5,     24,          31 ];
-NEMA17M = ["NEMA17M",  42.3, 40,     53.6/2, 25,     11,     2,     5,     20,          31 ];
-NEMA17M8= ["NEMA17M8", 42.3, 40,     53.6/2, 25,     11,     2,     8,     [280, 8, 4], 31 ];
-NEMA17S = ["NEMA17S",  42.3, 34,     53.6/2, 25,     11,     2,     5,     24,          31 ];
-NEMA16  = ["NEMA16",   39.5, 19.2,   50.6/2, 50.6/2, 11,     2,     5,     12,          31 ];
-NEMA14  = ["NEMA14",   35.2, 36,     46.4/2, 21,     11,     2,     5,     21,          26 ];
-NEMA23  = ["NEMA23",   56.4, 51.2,   75.7/2, 35,   38.1/2, 1.6,   6.35,    24,        47.1 ];
+NEMA17  = ["NEMA17",   42.3, 47,     53.6/2, 25,     11,     2,     5,     24,          31];
+NEMA17M = ["NEMA17M",  42.3, 40,     53.6/2, 25,     11,     2,     5,     20,          31];
+NEMA17M8= ["NEMA17M8", 42.3, 40,     53.6/2, 25,     11,     2,     8,     [280, 8, 4], 31];
+NEMA17S = ["NEMA17S",  42.3, 34,     53.6/2, 25,     11,     2,     5,     24,          31];
+NEMA16  = ["NEMA16",   39.5, 19.2,   50.6/2, 50.6/2, 11,     2,     5,     12,          31];
+NEMA14  = ["NEMA14",   35.2, 36,     46.4/2, 21,     11,     2,     5,     21,          26];
+NEMA23  = ["NEMA23",   56.4, 51.2,   75.7/2, 35,   38.1/2, 1.6,   6.35,    24,        47.1];
 
 stepper_motors = [NEMA14, NEMA16, NEMA17S, NEMA17M, NEMA17, NEMA23];